1. Field of the Invention
The present invention relates generally to an electrical connector, and more particularly to an improvement in an electrical connector which has a housing in which a flat circuit device, such as a flexible printed circuit board (hereinafter, referred to as an FPC) or a flexible flat cable assembly (hereinafter, referred to as an FFC), is inserted, a plurality of conductive contacts arranged in the housing for coming into press-contact with connecting terminals provided on the flat circuit device inserted in the housing, holding means for engaging with the flat circuit device inserted in the housing so as to hold the same to be prevented from getting out of the housing unwillingly and releasing means for releasing the flat circuit device from holding by the holding means.
2. Description of the Prior Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
A flat circuit device, such as a relatively small-sized FPC or FFC, used in electronic apparatus of various kinds is often mounted on a main solid circuit board, on which various electrical parts are directly mounted, with an electrical connector which is mounted to and connected electrically with the main solid circuit board. The electrical connector has a plurality of conductive contacts, an end portion of each of which is connected electrically with a conductive circuit pattern portion formed on the main solid circuit board and which are provided for coming into contact with connecting terminals provided on the flat circuit device, and is operative to connect electrically each of the connecting terminals provided on the flat circuit device, through the conductive contacts, with the conductive circuit pattern portion formed on the main solid circuit board.
A first type of previously proposed electrical connector used for mounting a flat circuit device, such as an FPC, on a main solid circuit board, is provided with a housing made of insulator, which is mounted on the main solid circuit board and has an opening through which at least a part of the flat circuit device is inserted into the housing. In the housing, a plurality of conductive contacts are provided to be arranged along the opening and connected electrically with circuit terminals provided on the main solid circuit board. These conductive contacts are operative to come into contact respectively with a plurality of connecting terminals provided on the flat circuit device when the flat circuit device is inserted into the housing through the opening provided thereon. The previously proposed electrical connector of the first type is also provided with a conductive shell which covers partially the housing and is grounded to be operative to contribute to adjustment on characteristic impedance of each of the conductive contacts and to shield the conductive contacts in the housing from electromagnetic wave noises coming from the outside. The previously proposed electrical connector of the first type is further provided with an actuator which is provided to be rotatable in regard to the housing so as to engage with each of the conductive contacts arranged in the housing. When the actuator is rotated in a first direction in regard to the housing, an operating portion of each of the conductive contacts is moved by the actuator to put the conductive contact in press-contact with a corresponding one of the connecting terminals provided on the flat circuit device, and then, when the actuator is rotated in a second direction opposite to the first direction in regard to the housing, the conductive contacts put in press-contact with the connecting terminals provided on the flat circuit device are released from the press-contact with the connecting terminals. With the conductive contacts put in the press-contact with the connecting terminals provided on the flat circuit device, the flat circuit device is put in electrical connection with the main solid circuit board.
A second type of previously proposed electrical connector used for mounting the flat circuit device on the main solid circuit board is provided with a housing mounted on the main solid circuit board, a plurality of conductive contacts and a conductive shell in such a manner as mentioned above but is not provided with an actuator rotatable in regard to the housing. In the previously proposed electrical connector of the second type, when the flat circuit device is inserted into the housing through an opening provided thereon, each of the conductive contacts provided in the housing to be arranged along the opening is automatically put in press-contact with a corresponding one of connecting terminals provided on the flat circuit device. That is, the flat circuit device is put in electrical connection with the main solid circuit board by means of only inserting correctly the flat circuit device into the housing through the opening provided thereon.
In the above-mentioned previously proposed electrical connector with or without the actuator rotatable in regard to the housing, when the flat circuit device is inserted into the housing through the opening provided thereon and the conductive contacts provided in the housing are put in press-contact with the connecting terminals provided on the flat circuit device so that the flat circuit device is put in electrical connection with the main solid circuit board, it is required to prevent the flat circuit device inserted in the housing from getting out of the housing unwillingly. It is a matter of course that it is necessary for the flat circuit device inserted in the housing to be held stably so as not to get out of the housing unwillingly in order to keep the conductive contacts provided in the housing properly in a condition of press-contact with the connecting terminals provided on the flat circuit device.
There has been also proposed previously an electrical connector belonging to the above-described first type having the housing, the conductive contact, the conductive shell and the actuator, which is provided with holding means for engaging with a flat circuit device, such as an FPC or an FFC, inserted in the housing so as to hold the same to be prevented from getting out of the housing unwillingly, as shown in, for example, the Japanese patent application published before examination under publication number 2008-52993 (hereinafter, referred to as published patent document 1).
In addition, there has been further proposed previously an electrical connector belonging to the above-described second type having the housing, the conductive contact and the conductive shell, which is provided with holding means for engaging with a flat circuit device, such as an FPC or an FFC, inserted in the housing so as to hold the same to be prevented from getting out of the housing unwillingly, as shown in, for example, each of the Japanese patent application published before examination under publication number 2008-192574 (hereinafter, referred to as published patent document 2) and the Japanese patent application published before examination under publication number 2011-40246 (hereinafter, referred to as published patent document 3).
In the electrical connector shown in published patent document 1, the holding means (a locking portion 11c) is formed in a part of the conductive shell (a shield plate 11) to be able to seesaw with an engaging end portion (a nail portion 11d) curved to the inside of the conductive shell. The holding means shifts its position in response to a movement of the actuator (an actuator 9) provided to be rotatable in regard to the housing (a housing 3).
Then, when the actuator is rotated in a first direction in regard to the housing after the flat circuit device (an FPC 21) is inserted into a receiving space (an FPC receiving space 34) provided in the housing, each of the conductive contacts (first contacts 5, second contacts 6) provided in the housing is caused to shift its position by a cam (a cam portion 92 or 93) formed on the actuator so as to be put in press-contact with a corresponding one of connecting terminals provided on the flat circuit device inserted in the housing and the holding means is caused to shift its position by a com (a cam portion 94) formed on the actuator so as to cause the engaging end portion of the holding means to engage with an engaging portion (a recess 21a) formed on the flat circuit device. As a result, the flat circuit device inserted in the housing is prevented from getting out of the housing unwillingly.
After that, when the actuator is rotated in a second direction opposite to the first direction in regard to the housing under a condition wherein the engaging end portion of the holding means engages with the engaging portion formed on the flat circuit device, the cam (the cam portion 94) formed on the actuator allows the holding means to release the engaging end portion of the holding means from the engagement with the engaging portion formed on the flat circuit device. As a result, the flat circuit device is put in a condition to be able to get out of the housing.
Further, in the electrical connector shown in published patent document 2, the conductive shell (a shell 4) is provided to be rotatable to the housing (a housing body 2) and the holding means (a leg portion 46) in the form of a leaf spring is formed in a part of the conductive shell. The holding means has an engaging projection (44) formed at an end of the holding means to be curved to the inside of the conductive shell.
When the flat circuit device (an FPC) is inserted into the housing through the opening (an opening 21) provided thereon under a condition wherein the conductive shell is positioned to keep lying down on the housing so as to be close in its entirety to the housing, each of the conductive contacts (upper contacts 31, lower contacts 32) provided in the housing is caused to be put in press-contact with a corresponding one of connecting terminals provided on the flat circuit device inserted in the housing and the engaging projection formed on the holding means is caused to engage with an engaging portion (an FPC engaging hole 2) provided on the flat circuit device. As a result, the flat circuit device inserted in the housing is prevented from getting out of the housing unwillingly.
After that, when the conductive shell is rotated to be positioned to keep rising from the housing under a condition wherein the engaging projection formed on the holding means is put in engagement with the engaging portion formed on the flat circuit device, the holding means formed in the conductive shell shifts its position in response to a movement of the conductive shell so as to release the engaging projection provided on the holding means from the engagement with the engaging portion formed on the flat circuit device. As a result, the flat circuit device is put in a condition to be able to get out of the housing.
In the case of the previously proposed electrical connector disclosed in published patent document 1, which has the holding means operative to shift its position in response to the rotational movements of the actuator provided to be rotatable in regard to the housing, the actuator provided to be rotatable in regard to the housing is required and this results in problems or disadvantages that the number of constitutive parts of the electrical connector increases undesirably and a production cost of the electrical connector rises disagreeably.
Further, it is necessary for causing the holding means to engage with or disengage from the flat circuit device inserted in the housing to rotate the actuator in regard to the housing and this results in undesirable increase in an open space around the electrical connector. Besides, since the conductive shell is shaped to cover only an upper surface of the housing opposite to a lower surface of the same facing the main solid circuit board and side surfaces of the housing opposite each other in the direction along which the conductive contacts are arranged, a contribution by the conductive shell to the adjustment on characteristic impedance of each of the conductive contacts is inevitably reduced and a shielding effect by the conductive shell to the conductive contacts against the electromagnetic wave noises can not be obtained sufficiently.
In the case of the previously proposed electrical connector disclosed in published patent document 2, which has the conductive shell provided to be rotatable in regard to the housing and the holding means formed in the part of the conductive shell, since the conductive shell is operative to rotate in regard to the housing, any part of the conductive shell can not be used for fastening the electrical connector to the main solid circuit board so that a separate holding-down member for fastening the electrical connector to the main solid circuit board is required and this results in problems or disadvantages that the number of constitutive parts of the electrical connector increases undesirably and a production cost of the electrical connector rises disagreeably. In addition, in this case also, since the conductive shell provided to be rotatable in regard to the housing is shaped to cover only an upper surface of the housing opposite to a lower surface of the same facing the main solid circuit board and side surfaces of the housing opposite each other in the direction along which the conductive contacts are arranged, a contribution by the conductive shell to the adjustment on characteristic impedance of each of the conductive contacts is inevitably reduced and a shielding effect by the conductive shell to the conductive contacts against the electromagnetic wave noises can not be obtained sufficiently.
On the other hand, in the electrical connector shown in published patent document 3, the conductive shell (a conductive shell 14) for covering partially an outside surface of the housing (a housing 11) is provided with the holding means (a locking member 20) formed to extend into the housing for holding the flat circuit device (an FPC 40) inserted in the housing through the opening (an opening 12) provided thereon. Further, the housing is provided with the releasing means (a releasing member 30) formed in a body on the housing to be movable with a first end portion projecting from the inside of the housing toward the outside of the conductive shell and a second end portion engaging with the holding means.
The holding means has an engaging projection (23) formed to be put in engagement with an engaging edged recess (43; 44) provided on the flat circuit device inserted in the housing for holding the flat circuit device and a resilient arm portion (22) for supporting the engaging portion to be shiftable in position. The second end portion of the releasing means is operative to engage with the resilient arm portion of the holding means.
On the side of an upper surface of the housing (a surface of the housing opposite to a lower surface of the housing facing a solid circuit board on which the housing is mounted.), the first end portion of the releasing means projects upward from the housing toward the outside of the conductive shell covering the upper surface of the housing.
Then, when the flat circuit device is inserted into the housing through the opening provided thereon, the engaging portion of the holding means is put in engagement with the engaging edged recess provided on the flat circuit device inserted in the housing to hold the flat circuit device. As a result, the flat circuit device inserted in the housing is prevented from getting out of the housing unwillingly.
After that, when the first end portion of the releasing means projecting upward from the housing toward the outside of the conductive shell is pushed down toward the inside of the conductive shell, the second end portion of the releasing means engages with the resilient arm portion of the holding means to cause the same to shift in position so that the engaging portion supported by the resilient arm portion of the holding means is shifted in position to disengage from the engaging edged recess provided on the flat circuit device. As a result, the engaging portion of the holding means is released from the engagement with the engaging edged recess provided on the flat circuit device and thereby the flat circuit device inserted in the housing is put in a condition to be able to get out of the housing.
With the previously proposed electrical connector, in which the conductive shell is provided with the holding means formed to extend into the housing for holding the flat circuit device and the housing is provided with the releasing means formed in a body on the housing to be movable, as disclosed in published patent document 3, the disadvantages encountered with each of the previously proposed electrical connector disclosed in published patent document, which has the actuator provided to be rotatable in regard to the housing and the holding means formed on a part of the conductive shell, and the previously proposed electrical connector disclosed in published patent document 2, which has the conductive shell provided to be rotatable in regard to the housing and the holding means formed on a part of the conductive shell, are desirably avoided.
However, in the electrical connector proposed previously, as disclosed in published patent document 3, to be used for mounting the flat circuit device, such as the FPC, on the solid circuit board, which has the conductive shell provided with the holding means formed to extend into the housing for holding the flat circuit device and the housing provided with the releasing means formed in a body on the housing to be movable, the first end portion of the releasing means projects upward from the housing toward the outside of the conductive shell and it is necessary to push down the first end portion of the releasing means projecting upward from the housing when the flat circuit device inserted in the housing is released from holding by the holding means. Therefore, it is difficult to reduce a measure of the housing including the first end portion of the releasing means in a direction perpendicular to each of the upper and lower surfaces of the housing, that is, a measure of the housing in its thickness, sufficiently to obtain a thin circuit board assembly, and this may prevent each of various electrical or electronic parts mounted on the solid circuit board from being reduced in a measure of thickness.
Further, in the electrical connector proposed previously to be disclosed in published patent document 3, since a manipulation for pushing down the first end portion of the releasing means projecting upward from the housing is required to cause the flat circuit device inserted in the housing to be released from the holding by the holding means. It is necessary to keep an open space enough to conduct the manipulation for pushing down the first end portion of the releasing means above the first end portion of the releasing means projecting upward from the housing. Consequently, the electrical connector proposed previously to be disclosed in published patent document 3 is not able to be put in practical use under a condition wherein, when the housing is mounted on the solid circuit board, the open space enough to conduct the manipulation for pushing down the first end portion of the releasing means can not be obtained above the first end portion of the releasing means projecting upward from the housing on the solid circuit board.